1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same. More particularly, the present invention relates to a semiconductor device having a wiring which passes through a substrate such as a semiconductor device in a packaged form in which a solid-state imaging device or the like is air-tightly sealed. The present invention relates also to a method of manufacturing the same.
2. Description of Related Art
As one example of miniaturization of a solid-state image sensor, there is disclosed a method for keeping a image sensor area in a sealed state in Japanese Unexamined Patent Application Publication No. 2006-128713 (hereinafter referred to as “Patent Document 1”) or the like. The method includes forming an adhesive layer in a peripheral portion outside of the image sensor area, disposing a transparent plate such as glass above the solid-state image sensor to adhere the transparent plate by an adhesive layer for sealing.
A method for electrically connecting an external electrode of the solid-state image sensor thus configured is as follows: a dry etching method or the like is used to form a through hole which reaches a pad electrode made of aluminum or the like disposed on an active surface from a surface opposite to the active surface of the solid-state image sensor; an inner wall of the through hole is formed with an insulating layer for ensuring insulation from a silicon substrate constituting the solid-state image sensor; and a conductive layer, made of copper or the like, for electrically connecting with the pad electrode filled within the through hole or deposited to cover a side wall of the through hole.
When the external electrode is electrically connected from a rear surface of the active surface, it may become possible to achieve packaging of a solid-state imaging device by the same size as that of the solid-state image sensor, thereby enabling miniaturization of the solid-state imaging device.